Updated 12:10 p.m.| Seven-term Minnesota GOP Rep. John Kline announced Thursday he will not run for re-election, putting Republicans in a tough spot to hold the southeastern Minnesota district in a presidential year. "It has been and will continue to be a privilege serving the men and women of Minnesota’s 2nd District for the next 16 months,” he said in a statement Thursday morning.

Kline was first elected in 2002 and won re-election last November by 17 points. But his seat has been a perennial Democratic target since President Barack Obama narrowly carried the district twice. His retirement announcement is prompting TheRothenberg & Gonzales Political Report /Roll Call to move the race from Safe Republican to Tossup.Adding to Republican challenges this cycle is that there's no gubernatorial or Senate race in Minnesota. And as the state is not competitive at the presidential level, the party is unlikely to have a strong turnout operation in place to aide down-ballot contests. Even before Kline’s announcement, Democrats were enthused about two female candidates in the race: health care executive Angie Craig and physician Mary Lawrence.Lawrence, who loaned her campaign $500,000 in the second quarter, had more than $1 million in the bank at the end of the period. Craig had $231,000 in the bank by the end of June. On the Republican side, multiple party operatives said to expect a crowded primary. Possible candidates include:

State Sen. Dave Thompson, a former conservative radio host who represents a district south of the Twin Cities. Thompson ran for governor, but dropped out before the primary.

State Rep. Rod Hamilton, who first came to the state legislature in 2004.

David Gerson, a libertarian who unsuccessfully waged a primary against Kline in both 2012 and 2014.

GOP operatives also mentioned former Gov. Tim Pawlenty's wife, Mary, as a possible wildcard candidate. She is a former state court judge.

In Minnesota, the state party endorses candidates. Often the candidates who do not receive the endorsement drop out, allowing the endorsed candidate to secure the party's nod.

But as the Minnesota Republican Party's clout has diminished in recent years, it's unclear whether the endorsement will be heeded.

Kline will be termed out of his chairmanship of the Education and Workforce Committee at the end of this Congress. Republican operatives in Minnesota said his fundraising had slowed in the August recess, a sign he wasn’t gearing up for re-election. Kline emphasized that he's won't be slowing down during his remaining time in Congress.

“I want to be clear – much more work lies ahead in the next 16 months. As Chairman of the House Education and the Workforce Committee I look forward to replacing No Child Left Behind and expanding access to higher education," he said in the statement.